/*
 * Copyright (c) 2016 Zibin Zheng <znbin@qq.com>
 * All rights reserved
 */

#include "multi_button.h"

#define EVENT_CB(ev)   if(handle->cb[ev])handle->cb[ev]((Button*)handle)
//button handle list head.
static struct Button* head_handle = NULL;

/**
  * @brief  Initializes the button struct handle.
  * @param  handle: the button handle strcut.
  * @param  pin_level: read the HAL GPIO of the connet button level.
  * @param  active_level: pressed GPIO level.
  * @retval None
  */
void button_init(struct Button* handle, uint8_t(*pin_level)(), uint8_t active_level)
{
    memset(handle, 0, sizeof(struct Button));
    handle->event = (uint8_t)NONE_PRESS;
    handle->hal_button_Level = pin_level;
    handle->button_level = handle->hal_button_Level();
    handle->active_level = active_level;
}

/**
  * @brief  Attach the button event callback function.
  * @param  handle: the button handle strcut.
  * @param  event: trigger event type.
  * @param  cb: callback function.
  * @retval None
  */
void button_attach(struct Button* handle, PressEvent event, BtnCallback cb)
{
    handle->cb[event] = cb;
}

/**
  * @brief  Inquire the button event happen.
  * @param  handle: the button handle strcut.
  * @retval button event.
  */
PressEvent get_button_event(struct Button* handle)
{
    return (PressEvent)(handle->event);
}

/**
  * @brief  Button driver core function, driver state machine.
  * @param  handle: the button handle strcut.
  * @retval None
  */
void button_handler(struct Button* handle)
{
    uint8_t read_gpio_level = handle->hal_button_Level();

    //ticks counter working..
    if((handle->state) > 0) handle->ticks++;

    /*------------button debounce handle---------------*/
    if(read_gpio_level != handle->button_level)   //not equal to prev one
    {
        //continue read 3 times same new level change
        if(++(handle->debounce_cnt) >= DEBOUNCE_TICKS)
        {
            handle->button_level = read_gpio_level;
            handle->debounce_cnt = 0;
        }
    }
    else     //leved not change ,counter reset.
    {
        handle->debounce_cnt = 0;
    }

    /*-----------------State machine-------------------*/
    switch (handle->state)
    {
        case 0:
            if(handle->button_level == handle->active_level)  	//start press down
            {
                handle->event = (uint8_t)PRESS_DOWN;
                EVENT_CB(PRESS_DOWN);
                handle->ticks = 0;
                handle->repeat = 1;
                handle->state = 1;
            }
            else
            {
                handle->event = (uint8_t)NONE_PRESS;
            }

            break;

        case 1:
            if(handle->button_level != handle->active_level)   //released press up
            {
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);
                handle->ticks = 0;
                handle->state = 2;

            }
            else if(handle->ticks > LONG_TICKS)
            {
                handle->event = (uint8_t)LONG_RRESS_START;
                EVENT_CB(LONG_RRESS_START);
                handle->state = 5;
            }

            break;

        case 2:
            if(handle->button_level == handle->active_level)   //press down again
            {
                handle->event = (uint8_t)PRESS_DOWN;
                EVENT_CB(PRESS_DOWN);
                handle->repeat++;
                EVENT_CB(PRESS_REPEAT); // repeat hit
                handle->ticks = 0;
                handle->state = 3;
            }
            else if(handle->ticks > SHORT_TICKS)     //released timeout
            {
                if(handle->repeat == 1)
                {
                    handle->event = (uint8_t)SINGLE_CLICK;
                    EVENT_CB(SINGLE_CLICK);
                }
                else if(handle->repeat == 2)
                {
                    handle->event = (uint8_t)DOUBLE_CLICK;
                    EVENT_CB(DOUBLE_CLICK); // repeat hit
                }

                handle->state = 0;
            }

            break;

        case 3:
            if(handle->button_level != handle->active_level)   //released press up
            {
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);

                if(handle->ticks < SHORT_TICKS)
                {
                    handle->ticks = 0;
                    handle->state = 2; //repeat press
                }
                else
                {
                    handle->state = 0;
                }
            }

            break;

        case 5:
            if(handle->button_level == handle->active_level)
            {
                //continue hold trigger
                handle->event = (uint8_t)LONG_PRESS_HOLD;
                EVENT_CB(LONG_PRESS_HOLD);

            }
            else     //releasd
            {
                handle->event = (uint8_t)PRESS_UP;
                EVENT_CB(PRESS_UP);
                handle->state = 0; //reset
            }

            break;
    }
}

/**
  * @brief  Start the button work, add the handle into work list.
  * @param  handle: target handle strcut.
  * @retval 0: succeed. -1: already exist.
  */
int button_start(struct Button* handle)
{
    struct Button* target = head_handle;

    while(target)
    {
        if(target == handle) return -1;	//already exist.

        target = target->next;
    }

    handle->next = head_handle;
    head_handle = handle;
    return 0;
}

/**
  * @brief  Stop the button work, remove the handle off work list.
  * @param  handle: target handle strcut.
  * @retval None
  */
void button_stop(struct Button* handle)
{
    struct Button** curr;

    for(curr = &head_handle; *curr; )
    {
        struct Button* entry = *curr;

        if (entry == handle)
        {
            *curr = entry->next;
        }
        else
            curr = &entry->next;
    }
}

/**
  * @brief  background ticks, timer repeat invoking interval 5ms.
  * @param  None.
  * @retval None
  */
void button_ticks()
{
    struct Button* target;

    for(target = head_handle; target; target = target->next)
    {
        button_handler(target);
    }
}

